Apparatus for reducing rock and other mineral substances



May31,1932- MITCHELL 1,861,3 5

APPARATUS FOR REDUCING ROCK AND OTHER MINERAL SUBSTANCES Filed p 6, 1927 2 Sheets-Sheet 1 y 1932- .1. M. MITCHELL 1,861,315

APPARATUS FOR REDUCING ROCK AND OTHER MINERAL SUBSTANCES Filed Sept. 6, 1927 2 Sheets-Sheet 2 1 1 i nuulmum L THU ll [I Illlllll [ll HID J1 lllllHllllllllll II II INTI l I ll Ill IIHIIIIIIII Patented May 31 1932 UNITED STATES PATENT OFFICE JAMES MACDONALD MITCHELL, OF FLUSHING, NEW YORK.

Application filed September 6, 1927.

This invention relates to a method and ap paratus for reducing rock and other mineral substances.

In devices of this character now generally in use, the material is broken by compressive overload, centrifugal impact, or by rotary heaters. I11 all such devices, tremendous force is necessary in order to expeditiously reduce the material to proper size and shape.

It is an object of this invention to provlde a device which will reduce rock and other mineral substances to particles of more or less uniform size and shape and which will requre a comparatively small amount of force.

It is a further object of this invention to provide a device which will break rock by the forces of shear and torsion rather than by compressive overload or the other means 2% above enumerated.

It is another object of this invention to construct a device of this character which shall be exceedingly simple in operation, having few moving parts and which cannot, therefore, readily get out of order.

Other objects and advantages of the invention will in part become apparent and in part more clearly be brought out as the description proceeds.

3( In the accompanying drawings, I have illustrated an embodiment of the invention, but it is to be understood that the drawings are illustrative merely and are not to be construed as limiting the invention to the details of construction therein shown. It is obvious that many modifications may be made, all of which will fall within the scope of my invention as defined in the appended claims.

In the drawings:

Figure 1 is a front elevation of a machine constructed in accordance with my invention, the illustration being partly diagrammatic, and certain parts being broken away for clearness;

Figure 2 is a plan view, certain parts being shown in section;

Figure 3 is a plan View of a unit of my machine;

. Figure 4 is an elevation of the unit illustrated in Fig. 3

Serial No. 217,776.

Figure 5 is a plan view of one of the stationary elements; and

Figure 6 is a vertical section of part of the unit illustrated in Fig. 4.

Referring now to the drawings, the reference-numeral 1 indicates a base upon which is supported the casing 2. lVithin the casing is a frame 3, made of standard structural steel shapes, which supports a plurality of vertically spaced fixed plates or disks l. These plates may be of the shape illustrated in Fig. 5 or of any other shape as may be required by the particular construction of the frame. Resting upon each of the fixed plates in the space between adjacent plates, are the rotatable plates or disks 5. For the purpose of providing a slight clearance between the fixed and rotatable plates, each of the former is provided with an annular groove 6 in which is inserted the ring or annular rib 7 upon which the adjacent rotatable plate is supported.

All the plates, both fixed and rotatable, are provided with concentric apertures 8. These apertures may be of the shape illustrated in the drawings or they may be square or of other formation to suit the character of the work to be done, as may be determined b experiment. 1

The rotatable plates, here shown of circular shape, are provided with gear teeth 9 about their peripheries which mesh with pinions 10 on four shafts 11, located in the corners of the casing as clearly illustrated in Fig. 2. By this means, the rotatable plates are maintained centered with respect to each other and the fixed plates.

Motion is transmitted to the shafts 11 from two vertical motors 12, illustrated diagrammatically in Fig. 1. It will be understood, however, that any other desirable and convenient source of motive power may be substituted.

As will be notedfrom Fig. 1, the plates are of gradually decreasing thickness and the apertures of gradually diminishing size. The purpose of this arrangement is to reduce the material to fine particles as it passes from the larger through the smaller apertures. In Fig. 4 is illustrated a unit comprising three plates of equal thickness and having apertures of the same size. The central plate may be fixed and the two outside plates rotatable, or the arrangement may be reversed. This unit is used to break material into pieces of generally rectangular shape and uniform size.

The operation of the machine is simple and the principle involved is believed apparent. Material to be broken, such as rock, is introduced into the apertures in the plates and rotary motion is imparted to the rotatable plates. By this motion, a shearing force is set up between the plates and the material is thus shorn off. It will also be'clear that when the material is firmly held by adjacent plates, the rotation of one plate with respect to the other will cause torsion of the material which will assist in reducing it to required size and shape.

It will thus be seen that I have produced a device which will reduce rock and other mineral substances by the forces of shear and torsion and that the device is exceedingly simple in construction and operation.

lVhat I claim is:

1. A device for reducing rock and other mineral substances, including alternately fixed and movable members, said members being provided with centrally disposed registering apertures for the reception of the material to be reduced.

2. A device for reducing rock and other mineral substances, including superposed relatively movable members, registering apertures centrally located in said members into which the material is introduced, and means for moving some of the members, whereby the material will be reduced by shear and torsion.

8. A device for reducing rock and other mineral substances, including a plurality of superposed alternately fixed and rotatable members, registering aperture centrally located in said members into which the material is introduced, and means for rotating the rotatable members, whereby the material will be reduced by shearing action between the members. 7

4-. A machine for reducing rock and other mineral substances, including a plurality of superposed alternately fixed and rotatable members of gradually diminishing thickness, registering apertures in said members, said apertures being of gradually reduced dimensions to form a tapered recess into which the material is introduced, and means for rotating the rotatable members, whereby the material is reduced by shear and torsion.

5. A machine for reducing rock and other mineral substances, including a base, a casing on said base, a frame within said casing, a plurality of vertically spaced fixed plates supported by said frame, a plurality of rotatable plates supported on the fixed plates, centrally located registering apertures in said plates into which material is introduced, and means for rotating the rotatable plates, whereby the material is reduced by shear and torsion.

6. A machine for reducing rock and other mineral substances including members for firmly gripping the material at spaced points along an axis passing through the members, and mechanism for moving certain of said members with respect to others of said members to subject the material to a torsion with respect to said axis, whereby the material is sheared and thus reduced to a smaller size.

7. A machine for reducing rock and other mineral substances including superposed alternately fixed and movable members adapted to receive and firmly grip the material at spaced points along an axis passing through said members, and means for moving the movable members to subject the material to a torsion with respect to said axis, whereby the material is twisted about said axis and thus reduced to a smaller size.

8. A machine for reducing rock and other mineral substances including a plurality of superposed alternately fixed and rotatable members, apertures in said members in axial alignment into which the material is introduced and wherein it is firmly held by said members, and means for rotating the rotatable members, whereby the material is reduced by twisting it about its axis.

9. A device for reducing rock and other mineral substances including a rotatable reducing member and a fixed reducing member, said members being provided with centrally disposed registering apertures for the reception of material to be reduced, and a spacing element between said members comprising an annular rib disposed on one of said members and seating against the other of said members.

10. A machine for reducing rock and other mineral substances comprising a plurality of relatively movable members provided with centrally disposed registering apertures for the reception of material to be reduced, one of said members comprising means for gripping the material and another of said members constituting means coacting with the gripping means for subjecting the material to a torsion with respect to an axis passing through the material, whereby the material is sheared to smaller size.

In testimony whereof I aflix my signature.

JAMES MACDONALD MITCHELL. 

